The invention relates to multi-stage presses and more particularly to facilities in such press for transversely moving a gripper-carrying cradle over a plurality of transversely spaced workpiece-receiving stations of the press in a cyclic path so that the grippers can be operated to transfer workpieces among the several stations.
Existing facilities of this general type have several disadvantages. Firstly, such designs have suffered from inaccuracies due to excessive play in the cradle drive. In addition, such facilities have been adapted to move the cradle along an essentially semicircular path, with a first portion of the cyclic movement of the cradle being positively driven along the path and the return movement being effected by the restoring force of resilient biasing means. The resultant high acceleration forces generated in a direction perpendicular to the desired transverse component of movement of the cradle with such arrangement necessitates the reduction in operating speed of the machine, and thereby of machine efficiency, in order to avoid excessive damage to the machine parts.